There's a scandal brewing in Washington. It involves the Supreme Court, specifically Justice Harry A. Blackmun, who recently told an all-male club that the court was shifting dangerously to the right, was overworked and was lacking in decorum. That's not the scandal. The scandal is that there is no scandal.

Blackmun spoke at the Cosmos Club here, which is an organization of male chauvinists masquerading as intellectuals. Blackmun is a member. The club refuses to admit women and has several times voted to retain that policy. You might think that's the scandal, but I tell you it isn't. No one cares.

You only have to glance at this not terribly important incident to learn that Washington, like the Cosmos itself, is dozing through the 1980s. Here you have a justice of the Supreme Court speaking before a club whose policy it is not to admit women -- and no one complains. Had the good justice spoken before an organization that bars blacks, the roof would have collapsed on his head. Someone would have said that this is an indication of prejudice, at the very least toleration of it, and some member of Congress would have called for the justice's impeachment. It has been done for less. Justice William O. Douglas, for instance, was mauled by then Rep. Gerald Ford merely for writing an article in an avant-garde magazine.

But no one said a word about Blackmun. No one pointed out that the court frequently hears cases regarding sex discrimination, that sooner or later it will get into the matter of comparable pay, that inevitably abortion will be back on the docket and that these issues affecting women will be decided by a jurist who's a member of an all- male club. The issue is not whether the Cosmos has the right to bar women but whether Blackmun an obligation to appear fair and to take a stand against discrimination. The Cosmos, after all, isn't a golf club that's short on locker room space. Its members are chosen for accomplishment -- although their most singular accomplishment is to persist in thinking that no woman could meet this criterion.

But what exercised the town, at least the members of the Cosmos, was not sexism but that Blackmun's remarks made it into the paper. His talk, like all of those at the club, was supposed to be off the record. Yet three members (or guests) called The Washington Post under the delusion that what a Supreme Court justice says about the state and direction of the court is news.

As a result, the Cosmos has written its members reminding them of the rules, calling the incident "an embarrassment to all of us, to the club and, most importantly, to our speaker." Something awful happened. Remarks that should be of concern to all Americans wound up in print. What business is it of the country that a Supreme Cout justice thinks the court is overworked, that it's "moving to the right," going "where it wants to go . . . by hook or by crook?"

What's it to the people that Blackmun thinks that court conservatives have become the judicial activists they once decried? Who cares that he said "affirmative action was pretty much interred" and that some opinions exhibit "extremism" and a "lack of accommodation"? Why should the voters know that the court is "weary and overworked" or that when the last term ended Blackmun "was never so tired"?

The Cosmos is a pathetic institution, a collection of Washington's great 19th- century minds, and not something you should trouble yourself about. Blackmun is a different matter, though. He's not only a member of an organization that discriminates on the basis of sex, he spoke to it with the understanding that what he said would be kept secret from the people who pay his salary. It's as if the court could not possibly be of interest to the voters who, after all, will decide its direction in November.

So that's the scandal brewing in Washington. It is that a member of the Supreme Court belongs to a club that discriminates on the basis of sex, and almost no one cares. It is that he thinks that his observations on the court should be reserved for a select few -- and once again almost no one cares. Apathy is Washington's truest monument.